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Program: Iridium


As the program was originaly thought with 77 satellites, it was named after the 77th element in the periodical table: Iridium

The Iridium system is owned by Iridium LLC, an international consortium of 17 investor organizations representing telecommunications and industrial companies worldwide, with Motorola Satellite Communications Group serving as the prime contractor. The investors are: Iridium Africa Corporation, Iridium Canada, Inc., Iridium China (Hong Kong), Ltd., Iridium India Telecom Limited, Iridium Middle East Corporation, Iridium SudAmerica Corporation, Khrunichev State Research and Production Space Center of the Russian Federation, Korea Mobile Telecommunications of Korea, Lockheed Martin Corporation and Motorola, Inc. of the U.S., Nippon Iridium Corporation of Japan, o.tel.o communications GmbH of Germany, Pacific Electric Wire & Cable Co., Ltd. of Taiwan, Raytheon Company of the U.S., Sprint Corporation of the U.S., STET Group - Societa Finanziara Telefonica per Azioni of Italy, and Thai Satellite Telecommunications Co., Ltd. of Thailand.

The cost of the global system is close to $7 billion. The commercial launch date is 23 Sep 1998 Cost per satellite: $62 million

On 15 Aug 1999 the company filled for bankrupcy. In Feb 2000 Craig McCaw's Eagle River Investments provided $74.6 million. On 6 Mar 2000 McCaw's firm finaly said it was not interested in Iridium anymore; the firm wants to focus on data communication systems. Insurance paid $240 million for failed Iridium satellites.

The network officially closed on 17 Mar 2000 after selling 55,000 terminals (approx $3000 each). The limited service still available stopped on 24 Aug 2000.

But on 20 Nov 2000 the assets of Iridium LLC and its subsidiaries were sold to Iridium Satellite LLC for $25 million ($6.5 million in cash and $18.5 million in convertible debt). A few days later it was known that the DoD purchased 2 years of satellite telephony services from the new owner and would receive more than 15000 handsets and unlimited time usage (20000 government users). Contract worth $72 million. The contract has options that bring the total value to $252 million with service till Dec 2007. The system will be upgraded for classified services.

In Apr 2001, investors from Brazil, Australia and Saudi Arabia are said to own 61 percent of Iridium LLC, which causes a problem as foreign ownership should be limited to 25% to get a licence.

Dialup internet access is possible at 2.4 kbps and direct-internet data access tops at 10 kbps. FCC granted a new licence in July 2001 for a 3.5 MHz segment in both 1.990-2.025 and 2.165-2.200 GHz bands.

In Dec 2001, the company states that they do not intend to launch new satellites before 2010 and build new satellites before 2020! 14 spare satellites are waiting on the ground.

In Jul 2005, 66 satellites are operational and 11 are in orbital storage.


Iridium Next


Iridium Next (S2110) will replace the present constellation from 2017 on. Will offer higher bandwidth for data transmissions. Lockheed Martin and Thales Alenia Space were the 2 final bidders and Thales Alenia Space was finally selected. Coface, the French credit agency, commited to cover 95% of the $1.8 billion credit facility. 72 satellites will be launched and 9 ground spare built. The program is worth $2.9 billion (including launches and ground facilities). Orbital is in charge of payload and bus integration.
Satellites also host a secondary payload: the exactView payload for AIS monitoring for ExactEarth (procured from Harris Corporation).

Iridium Certus is a broadband service to provide upto 1.4 Mbps speeds.


First launched planned in 2015, in fact Jan 2017, on several vehicles including Falcon 9 and Dnepr. Completion of launches now 2018.

Iridium Next Specifications
Iridium Next Payload

Status: to be operational in 2017

External resources


http://www.iridium.com/

http://www2.satellite.eu.org/sat/vsohp/iridium.html
http://www.aireon.com/Home
http://www.rod.sladen.org.uk/iridium.htm

Technical data



Slots and planes of first constellation


slot satellites #
plane 1 (158) 62, 63, 64, 65, 66, 67, 68, 70, 72, 73, 74, 75
plane 2 (189) 11, 20, 22, 23, 24, 25, 26, 45, 46, 47, 48, 49, 69, 76, 71
plane 3 (221) 27, 28, 29, 30, 31, 32, 33, 55, 57, 58, 59, 60
plane 4 (252) 4, 5, 6, 7, 8, 19, 34, 35, 36, 37, 51, 61
plane 5 (284) 9, 10, 11, 12, 13, 14, 16, 50, 52, 53, 54, 56, 83, 84, 85, 86
plane 6 (316) 15, 17, 18, 20, 21, 38, 39, 40, 41, 42, 43, 44, 77, 79, 80, 81, 82

In early 1999 12 satellites were reported as failed

First constellation overview


Orbit type LEO
Orbit range 780 km, circular
Nb of satellites 66 + 7 backup
Nb of planes 6
Inclination 86.4°
Nb beams per satellite 48
Coverage 4700 km²
Modulation FNMA/TDMA
Mobile frequencies Uplink: L-band
Downlink: 1610-1626.5 MHz
Satellite mass 725 kg
Coverage all longitudes, 80N - 80S latitudes
Operational date 23 Sep 1998

TT&C: uplink: 29.1-29.3 GHz, downlink: 19.4-19.6 GHz


Slots and planes of second constellation


plane 1 (158) 145 143 140 148 150   144 149 146 142 157
plane 2 (189) 134 141 137 116 135 151 120 113 138 130 131
plane 3 (221) 117     123 126     121 118    
plane 4 (252) 119 122 128 107 132 129 127 133 125 136 139
plane 5 (284)               105 108    
plane 6 (316) 102 112 104 114 103 109 106 152 147 110 111



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